All of Keiji's bodypiercings are the symbol of a secret contract, which stipulates that all his needs would be completely taken care of by two twin brothers, Sou and You, in exchange for his becoming their pet.
However, the appearance of Miyama - Keiji's first actual friend - starts changing things. For the first time, Keiji finds it difficult to keep this dark secret buried, and the thin balance he tries to maintain unknowingly starts crumbling bit by bit...
Feelings like growing fond of someone, trust, friendship, love... each swaying feeling is depicted in this famous series, now in completed version!